WO2025082924A1

WO2025082924A1 - Determining when operational head needs replacing

Info

Publication number: WO2025082924A1
Application number: PCT/EP2024/078931
Authority: WO
Inventors: Robbert Freerk Johan Van Der Scheer; Joost Willem Frederik NENGERMAN; Arno KROEZEN
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2023-10-20
Filing date: 2024-10-15
Publication date: 2025-04-24
Anticipated expiration: 2026-04-20
Also published as: EP4541532A1

Abstract

The subject-matter of the present disclosure relates to a computer-implemented method of determining when an operational head (106) of a personal care appliance (100) needs to be replaced. The computer-implemented method comprises: monitoring (700) an operational parameter sensed by a sensor (114) of the personal care appliance, the operational parameter associated with operating the operational head; determining (702) values based on the operational parameter over time; determining (704) an energy used in operating the operational head over time based on the values; determining (706) that the operational head needs to be replaced based on changes of the energy over time; and sending (708) a signal indicating that the operational heads to be replaced in response to the determining that the operational head needs to be replaced.

Description

DETERMINING WHEN OPERATIONAL HEAD NEEDS REPLACING

FIELD OF THE INVENTION

The subject-mater of the present disclosure relates to personal care appliances and determining when an operational head of a personal care appliance requires replacing, plus transitory, or non-transitory, computer-readable media.

BACKGROUND OF THE INVENTION

Personal care appliances, such as hair cuting devices, often include a cuter. The cuter, when first installed to the personal care appliance, is sharp and cuts or shaves hair well. However, over time, the cuter or shaving device becomes more blunt and requires replacing.

Generating a replacing signal for a user can be difficult because different users have different hair types. For example, one user may have a dense beard with thick hair. Another use may have a sparse beard with finer hair. The former will blunt the cuter quicker than the later.

It is an aim of the subject-mater of the present disclosure to improve on the prior art.

US 2018/0236674 discloses an electric shaver in which a friction between cuting members of the cuting head is monitored, and the friction is processed to determine a condition of wear. It is based on a design of cuting members such that friction between them is related to their condition of wear in a predetermined way. For example, a contact area may change at different amounts of wear, or different materials may come into contact at different amounts of wear. The friction can be determined from a level of motor power.

SUMMARY OF THE INVENTION

The invention is defined by the claims.

According to a first aspect of the present invention, there is provided a computer- implemented method of determining when an operational head of a personal care appliance needs to be replaced, the computer-implemented method comprising: monitoring an operational parameter sensed by a sensor of the personal care appliance, the operational parameter associated with operating the operational head; determining values based on the operational parameter over time; determining an energy used in operating the operational head over time based on the values; determining that the operational head needs to be replaced based on changes of the energy over time; and sending a signal indicating that the operational heads to be replaced in response to the determining that the operational head needs to be replaced. By determining that the operational head needs replacing based on changes of the energy over time, the determination is based on how the personal care appliance operates on that specific user. In this way, the determination is tailored to the specific user.

In an embodiment, the determining the values based on the operational parameter over time comprises: measuring, using the sensor, real time values of the operational parameter; and subtracting free-running values of the operational parameter from the real time values of the operational parameter.

In an embodiment, the subtracting the real time values based on operational parameter from the free-running value of the operational parameter comprises: monitoring a real time free-running value of the operational parameter; and subtracting the real time free-running value of the operational parameter from the real time value of the operational parameter.

In an embodiment, the monitoring the real time free-running value of the operational parameter comprises determining the real time free-running value of the operational parameter by: using a low-pass filter on the real time values of the operational parameter to discard values above a threshold; calculating a moving minimum value from the real time values of the operational parameter; or calculating a moving 1st percentile value from the real time values of the operational parameter.

In an embodiment, the determining that the operational head needs to be replaced based on changes of the energy over time comprises: calculating a cumulative energy over time using the determined energy; comparing the cumulative energy to an energy threshold; and determining that the operational head needs to be replaced based on the comparison.

In an embodiment, the determining that the operational head needs to be replaced based on the comparison comprises determining that the operational head needs to be replaced when the cumulative energy is greater than or equal to the energy threshold.

In an embodiment, the personal care appliance comprises a motor for operating the operational head, in-use, and wherein the operational parameter is power or current of the motor.

In an embodiment, the determining the energy used in operating the operational head over time based on the values based on operational parameter comprises integrating the determined values over time.

In an embodiment, the personal care appliance is a trimmer or a shaver, and the operational head is a trimmer.

In an embodiment, the sending a signal indicating that the operational head is to be replaced in response to the determining that the operational head needs to be replaced comprises sending a signal to a display device to display a notification to a user to replace the operational head.

In an embodiment, the display device is a remote device, or a display device mounted to the personal care appliance.

According to an aspect of the present invention, there is provided a transitory, or non- transitory, computer-readable medium, having instructions stored thereon that when executed by one or more processors, cause the one or more processors to perform the computer-implemented method of any preceding aspect or embodiment.

According to an aspect of the present invention, there is provided a personal care appliance comprising: a handle; a sensor coupled to the handle; an attachment for attaching an operational head to the handle; and a controller having a processor and storage, wherein the storage has instructions stored thereon that, when executed by the processor, cause the processor to perform the computer- implemented method of any preceding aspect or embodiment.

These and other aspects of the present invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present inventions may be best understood with reference to the accompanying figures, in which:

Fig. 1 shows a block diagram of a personal care appliance according to one or more embodiments;

Fig. 2 shows a series of parameter values captured over time for respective new and worn operational heads of the personal care appliance;

Fig. 3 shows operational values measured from a sensor of the personal care appliance over time, and their breakdown into a component attributable to operating the operational head and a component attributable to a free-running motor of the personal care appliance, according to one or more embodiments;

Fig. 4 shows a graph for use in determining the free-running values from the measured values, according to one or more embodiments;

Fig. 5 shows a graph showing cumulative energy over a number of shaves compared to a cumulative energy replacement threshold; and

Fig. 6 shows a flow chart summarising a computer-implemented method of determining whether an operational head of a personal care appliance requires replacing.

DETAILED DESCRIPTION OF THE EMBODIMENTS

At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware operational head, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, atributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others.

With reference to Fig. 1, a personal care appliance 100 according to one or more embodiments includes a handle 102, an atachment 104, an operational head 106, a power source 108, a controller 110, a motor 112, a sensor 114, and a display 116.

The personal care appliance 100 may be a hair removal appliance such as a trimmer or a shaver, for example. The operational head 106 is a device that performs and operation, e.g. hair removal. The operational head may be a trimmer. The trimmer includes a guard and a cuter. The cuter and the guard each comprise teeth which cut hair there between when the cuter moves reciprocally over the guard.

The atachment 104 attaches the operational head 106 to the handle 102.

The power source 108 may be a batery, e.g. a secondary, or rechargeable, batery.

The controller 110 may include storage and one or more processors. The storage includes electronic data in the form of instructions. The instructions, when executed by the one or more processors, may cause the one or more processors to perform the computer-implemented methods described herein. In this way, the storage may be non-transitory computer readable media. The instructions may also be provided as transitory computer-readable media when provided as a download to be stored on the storage.

The motor 112 may consume energy from the power source 108 when operating. This energy may be sensed by the sensor 114. The sensor sensed an operational parameter associated with operating the operational head. The operational parameter being current or power.

The display 116 may be mounted to an exterior surface of the handle 102 and communicatively linked to the controller so as to display indications generated by the controller.

With reference to Fig. 2, both graphs show operational parameter values cycling between values associated with cuting hair and values associated with a free-running motor. The values of a free- running motor are associated with the troughs 202 and the values of cuting hair are associated with the peaks 204. Also shown on each graph is an average value line 206, a value 208 which is the average plus 10% of a peak to peak signal swing of the operation parameter values, and a value 210 which is the average minus 10% of the peak to peak signal swing of the operational parameter values. The upper figure is associated with a brand-new cuter. The lower figure is associated with a worn cuter. It can be seen that the amplitude between values associated with cutting hair and values associated with a free- running motor (i.e. the peak to peak signal swing) is larger for the worn cutting element, and therefore the + and - 10% lines 208, 210, are farther apart.

Therefore, it can be seen that the operational parameter values can be used for determining when the operational head needs replacing since there are differences between worn and brand-new cutters.

In particular, by identifying a free running value of the operational parameter that is associated with a free-running motor, the distribution of operational parameter values can be monitored relative to the free running value. In this way, the peak to peak signal swing is used as an identifier of the amount of wear of the cutter.

The free running value and the peak to peak value are monitored in real time. The free running value is determined as a minimum value over a period of time (and hence it is also the lower peak value) and the upper peak value is determined as a maximum value over a period of time.

Embodiments provide a computer-implemented method of determining when an operational head of a personal care appliance requires replacing that addresses this need. The method includes monitoring an operational parameter sensed by a sensor of the personal care appliance, the operational parameter associated with operating the operational head; determining values based on the operational parameter over time; determining an energy used in operating the operational head over time based on the values; determining that the operational head needs to be replaced based on changes of the energy overtime; and sending a signal indicating that the operational heads to be replaced in response to the determining that the operational head needs to be replaced.

With reference to Fig. 3, the determining the values based on, or of, the operational parameter over time for each use comprises, for each use: measuring, using the sensor, real time values of the operational parameter; and finding a difference value, e.g., subtracting the real time values 302 of the operational parameter from a free-running value 306 of the operational parameter. The result of the subtraction is the values of the operational parameter 304.

Thus, an analysis is be made of the operational parameter relative to the free running value as explained above.

This method is shown in Fig. 3 when the free-running value 306 is constant. This is an approximation method.

With reference to Fig. 4, a more accurate method is provided where the wherein the subtracting the real time values of the operational parameter from the free-running value of the operational parameter comprises: monitoring a real time free-running value 402 of the operational parameter; and subtracting the real time value 404 of the operational parameter from the real time free- running value of the operational parameter over time. The result of the subtraction is the real time values 406. The method associated with Fig. 4 is more accurate than the method associated with Fig. 3 because the free-running values are in real-time, i.e. they are continually updated and not assumed to be constant. It is possible to obtain the real-time free running value 402 in various ways. For instance, it is possible to determine the real time free-running value of the operational parameter by using a low- pass filter on the real time values 404 of the operational parameter to discard values above a threshold. The threshold may be set at what is known to be a free-running value of a motor for example. Another way is to calculate a moving minimum value from the real time values of the operational parameter. The moving minimum uses a time window which moves with time. A minimum real time value 404 in the window is obtained and is used as the real-time free running value 402. Another way is to calculate a moving nth percentile value from the real time values of the operational parameter. The nth percentile may be a 1^st, 2^nd or even a 3^rd percentile, for example, although other percentiles may be used too.

With reference to Fig. 5, the determining that the operational head needs replacing based on changes of the energy over time comprises: calculating a cumulative energy over time using the determined energy; comparing the cumulative energy to an energy threshold; and determining that the operational head needs to be replaced based on the comparison.

The determining an energy used in operating the operational head over time based on the values comprises integrating the power values over time. This is visualised as integrating an area under a curve of the values 406 in Fig. 4. This may be done numerically rather than analytically. The cumulative energy is calculated by adding energy values for each shave to a total cumulative energy,

value of all shaves since the current cutter has been attached to the personal care appliance. The energy threshold, or energy replacement threshold,

may be predetermined.

As shown in Fig. 5, the time, or number of shaves, to reach the energy replacement threshold, is less for a heavy beard than a light beard. A heavy beard is defined as a beard that is dense and/or has thick hair. A light beard is a beard that is sparse and/or has thin hair. It will be appreciated that when the cumulative energy,

is greater than or equal to the energy threshold,

Finally, the sensing the signal indicating that the operational head needs to be replaced when the determining that the operational head needs to be replaced comprises sending a signal to the display 116 (Fig. 1) to display a notification to a user to replace the operational head. The display in Fig. 1 is a display mounted to the personal care appliance but the display may also be a display of a remote device.

With reference to Fig. 6, a computer-implemented method of determining when an operational head of a personal care appliance requires replacing is summarised as including the steps of: monitoring 700 an operational parameter sensed by a sensor of the personal care appliance, the operational parameter associated with operating the operational head; determining 702 values based on the operational parameter over time; determining 704 an energy used in operating the operational head over time based on the values; determining 706 that the operational head needs to be replaced based on changes of the energy over time; and sending 708 a signal indicating that the operational heads to be replaced in response to the determining that the operational head needs to be replaced. While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

Claim 1. A computer-implemented method of determining when a motor-driven hair cutter (106) of a hair cutting device (100) needs to be replaced, the computer-implemented method comprising: monitoring (700) an operational parameter sensed by a sensor (114) of the hair cutting device, the operational parameter associated with operating the hair cutter; determining (702) values based on the operational parameter over time; determining (704) an energy used in operating the hair cutter over time based on the values; determining (706) that the hair cutter needs to be replaced based on changes of the energy over time by: calculating a cumulative energy over time using the determined energy; comparing the cumulative energy to an energy threshold; and determining that the hair cutter needs to be replaced based on the comparison; and sending (708) a signal indicating that the hair cutter needs to be replaced in response to the determining that the hair cutter needs to be replaced.

Claim 2. The computer-implemented method of Claim 1, wherein the determining the values (406) based on the operational parameter overtime comprises: measuring, using the sensor, real time values (404) of the operational parameter; identifying a free running value of the operational parameter that is associated with a free-running motor; and obtaining a difference between the free-running value (402) of the operational parameter and the real time values of the operational parameter.

Claim 3. The computer-implemented method of Claim 2, wherein the obtaining a difference comprises: monitoring a real time free-running value of the operational parameter; and obtaining a difference between the real time free-running value of the operational parameter and the real time value of the operational parameter.

Claim 4. The computer-implemented method of Claim 3, wherein the monitoring the real time free-running value of the operational parameter comprises determining the real time free-running value of the operational parameter by: using a low-pass filter on the real time values of the operational parameter to discard values above a threshold; calculating a moving minimum value from the real time values of the operational parameter; or calculating a moving n* percentile value from the real time values of the operational parameter.

Claim 5. The computer-implemented method of any preceding claim, wherein the determining that the hair cutter needs to be replaced based on the comparison comprises determining that the hair cutter needs to be replaced when the cumulative energy is greater than or equal to the energy threshold.

Claim 6. The computer-implemented method of any preceding claim, wherein the operational parameter is the power of the motor of the motor-driven hair cutter.

Claim 7. The computer-implemented method of any preceding claim, wherein the determining an energy used in operating the hair cutter over time based on the values based on operational parameter comprises integrating the determined values over time.

Claim 8. The computer-implemented method of any preceding claim, wherein the hair cutting device is a shaver, and the hair cutter is a trimmer.

Claim 9. The computer-implemented method of any preceding claim, wherein the sending a signal indicating that the hair cutter is to be replaced in response to the determining that the hair cutter needs to be replaced comprises sending a signal to a display device (116) to display a notification to a user to replace the hair cutter.

Claim 10. The computer-implemented method of Claim 9, wherein the display device is a remote device, or a display device mounted to the hair cutting device.

Claim 11. A hair cutting device (100) comprising: a handle (102); a sensor (114) coupled to the handle; an attachment (104) for attaching an hair cutter to the handle; a motor (112) for driving the hair cutter; and a controller (110) having a processor and storage, wherein the storage has instructions stored thereon that, when executed by the processor, cause the processor to perform the computer- implemented method of any of Claims 1 to 10.

Claim 12. A transitory, or non-transitory, computer-readable medium, having instructions stored thereon that when executed by the controller of the hair cutting device of claim 11, cause the one or more processors to perform the computer-implemented method of any one of claims 1 to 10.